Chapter 39, Problem 32A

In the nineteenth century, the famous physicist Lord Kelvin made measurements of heat transfer in Earth’s crust and estimated Earth’s age to be very much less than the present estimate. What information did Kelvin not have that might have allowed him to avoid making his erroneous estimate?

To determine

The information that did not allow the Kelvin to correct estimate to Earth’s age.

Explanation of Solution

Introduction:

The amount of the radioactive material becomes half of initial amount in its half-life. So, the age of certain object can be found by calculating the amount of radioactive material in the sample of object.

The age prediction of any object by radioactive process is more accurate than other process. The age estimated by the heat transfer to Earth’s crust or any other process cannot provides the accurate result because these process are accurate only for the objects that have very small age. Lord Kelvin did not have the knowledge of radioactivity to avoid making his crronous estimate.

Conclusion:

Thus, Lord Kelvin did not know about the radioactivity until his estimate of Earth’s age.